Hopper closure for road spreader



April 15, 1958 E. G. F. SWEET 2,330,746

HOPPER CLOSURE FOR ROAD SPREADER Filed Sept. 26, 1955 Inventor EDM ND 6. E SWEET Att'ys United States Patent O" 2,830,746 HOPPER CLOSURE FOR ROAD SPREADER Edmund G. F. Sweet, Brantford, Ontario, Canada, as-

signor to Brantford Coach & Body Limited, Brantford, Ontario, Canada Application September 26, 1955, Serial No. 536,581 2 Claims. c1. 222 -410 This invention relates to a controlled outlet for fluidtype solid containers and has particular application to rotary type sand spreaders such as those shown in my copending application Serial No. 445,566 which issued on the 27th day of August 1957, as Patent Number 2,804,309.

It is an object of this invention to provide a controlled opening for fluid-type solid containers, for allowing or cutting off the flow of material and wherein the control for closing the opening is adapted to prevent damage to the closure apparatus in case a large hard object interferes with such closure.

This object is accomplished in accord with the invention by the provision of a closure member for an outlet opening movable between a position wherein said opening is closed and a position wherein said opening is open; a control member provided with direct operative connection to said closure member to cause it to move toward said open position and provided with a flexible operative connection to said closure member for moving it to said closed position.

It is an object of this invention to provide a controlled outlet for fluid-type solid containers wherein the edges of the walls defining such opening all terminate on the surface of a solid of revolution whereby the opening may be closed and opened by a cooperating closure member pivotally mounted about the axis of revolution of such surface. 7

It is an object of this invention to provide a controlled outlet for fluid-type solid containers such as those used in rotary sand spreaders as shown in my aplication Serial No. 445,566 and to operate in combination with the dispensing means.

By fluid-type solids I mean, solids which in their handling characteristics and particularly in their flow possess some of the qualities of a liquid. Examples of such solids would be sand, gravel, coal or grain.

Reference may now be had to the attached drawing in which:

Figure 1 shows the invention applied to a rotary sand spreader.

In my co-pending application Serial No. 445,566 there is shown a slowly revolving conveyor plate beneath the outlet of a sand hopper. Fences, rigidly mounted above the plate adjacent the hopper outlet act in cooperation with such plate to push the discharge of sand off the edge of the plate. Means are provided for guiding the sand which has been pushed 01f the edge of the plate onto a rapidly rotating spreading disc which revolves at a high rate of speed to spread the sand or other material by centrifugal force.

This invention relates to an outlet control which has particular application to a sand spreader as described above, when applied to the outlet connecting the hopper and the slowly revolving plate. In conection with the disclosure of this invention only the plate and hopper are shown; the remainder of the sand spreader elements are omitted for claritys sake.

In the drawing:

The hopper 10 is providedwith sloping walls 14 one of which defines a rectangular opening indicated by the dimensions A and B and which is provided with a controlled outlet 12 which forms the subject of this invention.

Controlled outlet 12 is defined by upper wall 16 and by the surface of rotary disc 18 the wall 16 extending outwardly from the upper edge of the rectangular opening and by side walls 20 and 22 which extend outwardly-from each of the side edges of said opening. The two side walls preferably have outer edges 24 and 26 which define a common surface of revolution and the said upper and lower walls 16 and 18 join said side walls along edge lines 28 and 29 respectively which terminate on such defined surface of revolution.

Pivotally mounted relative to the arcuate edged walls 20 and 22 is a closure member 30. The member 30 is provided with a curved closure surface 31 of substantially the same curvature as edges 20 and 22 which is freely pivotally mounted on a shaft 32 by two contiguously extending flanges 34 located on the outside of walls 20 and 22 respectively. The shaft 30 is mounted on the hopper wall 14 and is coaxial with the surface of revolution defined by arcuate edges 24-26. Thus the surface 31 moves along such edges.

The arcuate length of the surface 31 is suflicient to cover the opening which extends between the outer edges of the lower and upper walls 16 and 18 and the width is, as stated, suflicient to span the distance between the arcuate edges 24 and 26. The closure member 36 is free to rotate upward as through a sufiicient angle to completely expose the opening betwen upper, lower and side walls. Rigidly projecting laterally from the flange 34 is a stop 46 having a bearing surface 43 directed in the closure direction of rotation. A pin 42 mounted on the same Wall forms one anchorage for tension springs 44 Whose operation will be described hereafter. Rigidly mounted on the shaft 32 is a bell crank having one arm 48 extending to contact the bearing surface 43 and this same arm carries the second anchorage pin 50 for the tension spring 44. It will be seen that, but for the tension spring 44 the bell crank arm 48 would be free to move away from the stop member 40 in the closure direction without influencing the closure member 40 in this direction. The other arm 52 of the bell crank is connected to a control rod 54 and to operating means therefor such as a second operating lever 56 mounted on the base for the bin 10. Such base may well be a truck frame 58. The second operating lever 56 may be operated by any desired means and the operation of the invention is as follows:

With the operational parts in the position as shown, a motion of the second operating lever 56 clockwise (as seen in the drawing), will move the control rod 54 to the right and rotate the bell crank counterclockwise (as seen in the drawing). The bell crank arm 48 will, just before such operation, be in, or will make direct contact with, the stop member 40 and rotated by rod 54 will rotate the closure member 30 to expose the opening to whatever extent desired. Thus sand may be released from the hopper to flow out with the slowly rotating table 18.

If it is then desired to close the opening, the lever 56 is moved to the left, the rod 54 also moves to the left and the bell crank is rotated in clockwise direction. In normal operation, the closure member will follow the control arm 48 under the pull of the tension springs 44. In the event, however, of a large object (such as a rock) becoming wedged beneath the closure member 31, the said closure member will open against the tension springs 44 sutliciently to allow the passage of the said large object and will subsequently close under the action of the tension springs to the normal position in which bearing surface 43 of stop 40 contacts bell crank arm 48. In this way damage to the closure member 30 is avoided which would otherwise occur if there was a direct connection between closure member 30 and the bellcrank arm 48 for the closing movement.

What I claim as my invention is:

1. In a rotary type sand spreading apparatus provided with a hopper and a slowly revolving conveying plate mounted beneath said hopper for receiving the material therefrom, and means defining an opening in said hopper directed toward said plate, said opening being provided with a rotatably mounted closure member rotatable between 11 position wherein said opening is closed and a position wherein said opening is open, thereby defining a closure direction and an opening direction, an arm pivotally mounted concentrically with said closure member, abutment means having a bearing surface interconnecting said closure member and said arm to cause movement of said closure member toward open position in response to movement of said arm in said opening direction; and means resiliently biasing said closure member in said closure direction.

2. In a rotary type sand spreading apparatus as claimed in claim 1 wherein said means resiliently biasing said closure member comprises a tension spring attached at one end to said closure member and at the other end to said arm.

References Cited in the file of this patent UNITED STATES PATENTS 1,038,733 Durstewitz Sept. 17, 1912 1,857,495 Chase u May 10, 1932 2,644,614 Tanko et al. July 7, 1953 2,679,335 Bell May 25, 1954 2,718,986 Peoples Sept. 27, 1955 

